Stapling mechanism



April 29, 1941. F. A. scHl-:RMAN

sTAPLING MECHANISM Filed oet. 21. 1958 2 Sheets-Sheet l ZI@ 77) l@ 5INVENTOR.

ATTORNEY April 29, 1941. F, A, SCHERMAN u 2,239,935

STAPLING MECHANISM Fil'ed Oct. 21, 192,58 2 Sheets-Sheet 2 l n INVENTOR,

52 FEED 4. .5a/wwf MM MMM f ATTORNEY.;

`parts and reduceassembly costs.

Patented Apr. 29, 1941 STAPLING MECHANISM FredA. Scherman,Racine,\Wis.,assignor `towltgiax Tool-and Die Company, Racine,-Wis.,'acorporation of Wisconsin Application: october 21, lsasyseriai Normans 4Claims.

'This invention relates to improvements in staplingmechanisrn,

It is the primary object of the invention to provide a lnovel andsimplified type of lstapler kwhich-can readily be manufactured of simplestampings, requiring `few parts, providing substantially completeenclosure for the operating mechanism,.and avoiding any possibility ofstoppage.

The construction is such that the detailed organization of parts ishighly significant tothe Ygeneralobjectives as above stated, `andraccordingly. further objects of the .invention will be found in thefollowingzdisclosure.

In the drawings:

Fig, 1 is aperspectve View of the assembled apparatus.

Fig. 2 is a view of the apparatus in longitudinal section.

Fig. 3 is a'view taken in transverse section on the line 3-3 of Fig. 2.

Fig. 4 is a view taken in ltransverse section on the line 4-4 of Fig. 2.

Fig, 5 is a fragmentarybottom plan view of the stapling head as viewedon the line5-5 of Fig. 2.

Fig. 6 is a View showing `in perspective the several component parts lofthe device, with the exception of one of the casing elements, as suchpartsiappear when separated preparatory =to` assembly.

'Fig- 7 is a detail view in perspective showing the staple slidefollower.

` Like parts are identified by the same reference characters throughoutthe several views.

As the description proceeds, attention should r be given to theV mannerin which the several stampings comprising the frame and casing of thestapler `are each designed` to perform a variety of functions so as tominimize the number of The base 8 comprises a shallow box-like stampingmarginally provided at 9 with a flangewhich is preferably engaged by thecomplementary `flange of a shoe I of rubber or the like.

A shallow recess at 'I I assists in positioning the clinching die I2which is of generally conventional form. Upstanding ears I formedintegrally from the material of the base serve to support the pi-ntlebolt I5 upon which the stapling head oscillates on to the thrust of yaleaf spring I'I of the cantilever type which is provided at I8 `with anaperture engaged by a tongue I9 formed integrally from the base. Thetongue I9 lprojects into an opening in the basefwhlch receives the-endof thev spring. The spring ful' crumsacross the forward edge 2I of theportion `of v'thebaseadjacentopen-ing 20. 4

The centralstructural member ofthe oscillating-stapling head compriseslanlinverted channel havingl sides'provided with shouldered offsets at26and' terminatingrin marginal flanges 2l. The ilanges 21 Aserve asspacers' forthestamped sides 28 and 29 which havedownwardly-extending-ears 30 apertured at 300 to receive the pintle it,jwhereby the staplinghead is tiltably mounted. vThe'sides AZtand 29"(Figures 2 and 6) and interveningchannel 25 areconnected by vrivets 3|,'32 ,and 33. At a levelf above the channel 25 the sides'are alsoconnected by a bridge Vmember 35 `which has 'integraltonguesl36'extended through suitableapertures 3E0'in the sidesand thereupset vorfrivetedto connect the: sides together. Bridge `-inernber535is, like the base '8,'provided with an anchorage ior a cantileverspringwhich is shown at'SI. 'This' spring fulcrums onl the edge '38 ofthebridgemember adjacent'an opening 39 therein into which the tongue 40projects to engage the-'opening 4I inthe endof the spring, Spring 31supports the stapling plunger as will hereinafter be described. It isastronger spring than Spring I1.

-Extending longitudinally of the two sides 28 and 29 are inwardlyturned`flanges'42 and'43 respectively, which overliethe'top of theinverted channel 25 in spaced relation thereto. The sides of thechannel, above shoulders 26, are Ialso `in spaced relation to thesidesof the members 28 Iand `29, There is thus providedaboutthe upper side`and top portions of channe1-25 aguide slot of such dimensions as' tobeadapted toreceive the preformed stick of staplesas best shown in Fig. 3.Also-receivable'into the Iguide slotis the follower 46 which has acrosssectionf'sirnilar to that of the staples, and has'an upstanding lug4l traveling betweenthemargins of the inwardly directedfflanges 42andl43. The ears 48 andl 49 on Vthe follower 46 are 'engaged lby a rod50 encircled by alight compression spr-ing 5I andprovidedat itsend witha hook 52 releasably engageable vinthe opening 53 of the channel asshown in Fig. 2. The' follower is free to slide on `rodll to transmit tothe staples V45 the pressure ofthe springfSI which rimpels the staplessuccesi sively to the driveslot.

The side `frame members 28 and 29 of .the Vstapling head yare connectedat theirl forward ends by a front member 54 whichv is riveted`theretoiby` rivets 3|, 55 and 56 (see Fig. 2 and Fig..l 5). The frontwall '51 of thev member 54 tightly :abuts the frontmargins of the sideframe channel 25 (Figs. 2 and 5).

elements 28 and 29 but is spaced forwardly from the end of channel 25 toprovide a feed throat at 60 (Fig. 2 and Fig. 5) through which successivestaples are forced by the driving slide hereinafter to be described.

The front wall '5l is centrally notched at 6i as shown in Fig. 1, Fig. 2and Fig. 4, to receive spring B2 which is secured to the outer surfaceof wall 51 and extends first forwardly therefrom and then back uponitself through the slot 6| to a position normally underlying the top ofually forced forwardly out of the way by a staple impelled downwardlythrough the guideway 60, but the staple does not clear the spring untilit is substantially fully engaged with the work. If the pressure on thestaple is released before the staple is engaged with the work, thes-taple will be retracted by spring 62 with the feed slide, therebypreventing clogging of the guideway.

The feed Aslide or driver 63 is vertically reciprocable in the guideway6U Vand is connected with a manually operable` spring supported -plunger64 for its actuation. A rivet 65 (Fig. 2), serves as one means ofconnection of the slide to the plunger. The front wall 5l of the frontplate 54 is channeled at 66 to accommodate the movement of the rivet.

The, plunger may conveniently be made from a single stamping folded intoa hollow oblong form as shown in Fig. 2 and Fig. 6. Its sides areslotted at 61 to receive the transverse bolt 610 upon which the lowerend of the plunger is guided. The free margins of the stampingconstituting plunger 64 are provided with corresponding upwardlyextending lugsat 68, both of which are together received through thestamped opening 69 in the pressure plate T0. A wider opening 1I near theforward margin of plate 'l0 receives the lug 'I2 of the plunger stamping64, and also receives the lug 13 at the upper end of the drive slide 63.The lug 12 on the plunger stamping is slight-ly longer than lug 'i3 onthe driver slide to enable it to be upset or riveted over the surface ofplate lll, the same procedure being followed with lug 68. The upsettingof lug 'l2 wedges lug 13 of the driver` slide rigidly into unitaryconnection with the pressure plate l0. The lug of the driver slide isnotv upset because this slide is usually made of hard material.

An opening at 'Min the back of the tubular plunger 6d receives the endof the spring 3l whereby the plunger is normally supported in the raisedposition in which it is illustrated in the drawings. ered with a rubbercap 'I5 applied in the same manner that the rubber shoe l is applied tothe base of the instrument.

Theentire tilting stapling head is preferably encased in a two parthousing which tilts therewith and is readily removable. The housingelements 'i6 and 'i1 each comprise hollow box-like stampings havingtheir side flanges in marginal abutment on the vertical longitudinalcenter line of the apparatus. The bolt 610 which guides plunger 64extends through the sides of this case to connect such sides lat theforward end of the apparatus. Their only other means of connection isthe pivot bolt I upon which the stapling head pivots. This also extendsthrough the case and serves to connect the parts 18 and 1l thereoftogether.

There are only three exposed openings through 4the case. The spring 62which prevents clogging projects through a notch at 18 in the front endThis spring is grad- Pressure plate 'l0 is preferably covof the case.The rod 5l] which serves as a guide for the compression spring of thestaple follower projects through an opening at 'i9 in the rear end ofthe case. The plunger 64 projects upwardly through an opening at the topof the case `and is guided by the case for vertical reciprocation. Thusthe case performs a mechanical function of the device as well asconcealing the mechanism and thereby beautifying the entire assembly.

The staples used are inserted and fed through the feed slot under thepressure of spring 5| in much the usual manner. When the workfisinsented beneath the stapling head on the clinching anvil I2 the pad 15on the pressure plate 10 is struck to impel the driving slide 63downwardly, thus forcing the foremost staple down through the drive slot60 into engagement with the work. Since the spring l1 is weaker thanspring 3l, the initial pressure on the plunger will first tilt thestaplng head into engagement with the work, following which the drivingaction will occur as described.

I am aware that there are other stapling devices which are madepartially or principally of stampings, but the present device can bemade more cheaply than any other with which I am familiar because of theway in which the stampings are formed and the manner in which theycoact.

I claim:

l. In a device of 'the character described, the combination with 1a baseprovided with an aperture and having a tongue projecting into theaperture, of a leaf spring fulcrumed across the top of the base adjacentthe aperture and remote from the tongue and -provided with an opening inwhich said tongue is engaged for releasably securing said spring againstdisplacement, a stapling -head pivot/ally `connected with the base forlimited movement with respect thereto and provided with a part engagedby the end of said spring remote from said base, the limit of movementof said head andthe point of engagement of said spring therewith beingsuch as to urge said head toward one extreme of its movement and tomaintain said spring under slight initial deflection at such extreme.

2. In a device of the character described, a stapling head :comprisingside plates and an inverted channel connecting said side plates andprovided at its top with a transverse web having an openingtherewithin,said channel having marginal anges connected with the side plates andoffset -to provide a staple guideway vbetween said plates and web, afollower movable in the guideway, a guide rod upon which said followeris slidable, said rod beingdisposed between said plates and above saidweb, spring means on said rod, rand a reversely curved hook at the endof said rod extending about said web and engaged with the openingtherein from beneath for maintaining said rod in position and sustainingthe compression of said spring.

3. In a device of the character described, a stapler head framecomprising a pair of side plates, a plunger, means guiding said plungerfor reciprocation between said plates, means connecting said platescomprising a spring anchorage, and a leaf spring engaged in saidanchorage and having an end in supporting relation to said plunger.

4. In a device of theV character described, a stapling head comprising apair of side plates having apertures, a connecting web having tonguesextending through said iapertures and riveted upon said plates tomaintain their assembly, said Web having a `central `opening and a ngerprojecting into said opening, a plunger reciprocable between saidplates, means for guiding said plunger for recipr-ocation, ya leafspring having a free end engaged With said plunger .and provided with anopening in Which said nger is engaged, said spring being fulfcrumed overthe edge of said web adjacent the opening therein, whereby said springhas a `cantilever' mounting yon said frame.

FRED A. SCHERMAN.

